JPH06885U - Vehicle display - Google Patents

Abstract

(57) [Summary] [Structure] The first polarizer 9 and the first polarizer 1 are provided on the surface of the display 7.
A quarter wave plate 10 is provided. The second polarizing plate 11 and the second 1/90 which are different from each other in the polarization axis by 90 degrees with respect to the polarization axis of the first polarizing plate 9.
A cover member 13 composed of a four-wave plate 12 and a quarter-wave plate 1
The display 7 and the combiner 3 are provided so as to be opposed to each other by a predetermined angle. [Effect] Reflection of the sunlight S to the combiner 3 side is suppressed by the cover member 13, so that the visibility of the display image 15 and the deterioration of the display 7 due to the sunlight S can be suppressed more than before.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a so-called head-up display suitable for use as a display device for a vehicle.

[0002]

[Prior art]

 Driving information such as vehicle speed, mileage, remaining amount of fuel, or time is projected from the display by projecting it on a light-transmissive metal thin film provided on the combiner in front of the driver, for example, on the inner surface of the windshield by means of vapor deposition or the like. A display device has been developed in which a display image based on the display light rays is formed in the front visual field outside the windshield so that it can be seen as if it overlaps with the scenery in the visual field. For example, JP-A-3-200426 and 2004247. It is disclosed in the public information.

[0003]

[Problems to be solved by the device]

 In such a display device, when sunlight enters the vehicle interior from the windshield, it may be incident back to the display unit. In this case, the sunlight is reflected on the surface of the display unit and radiated to the combiner side, The displayed image is washed out and the visibility is reduced.

In order to solve such a problem, for example, by applying a non-reflective coating to the surface of the display by using a non-reflective member disclosed in Japanese Utility Model Application Laid-Open Nos. 4-39932 and 55418. It may be possible to prevent sunlight from shining on the combiner, but perfect non-reflection is impossible, and the reflectivity of about 0.2% is currently the limit. Therefore, when sunlight of 10 ⁶ cd / m ² or more is incident, about 2000 cd / m ² of reflected light is applied to the combiner, which is enough to confuse the displayed image and still reduces the visibility. I cannot escape.

[0005]

Means for Solving the Problems The present invention makes a display image corresponding to the display light into a virtual image by reflecting a display light from a display device toward the driver with a combiner arranged in front of the driver. In the vehicular display device for forming an image in front of the driver, a first polarizing plate and a first quarter-wave plate are provided on the surface of the display, and the polarizing axis of the polarizing plate is 90 °. A cover member composed of a second polarizing plate having a different polarization axis and a second quarter-wave plate is provided between the display and the combiner such that the both quarter-wave plates face each other. It is installed at an angle.

[0006]

[Action]

 Reflection of sunlight entering the vehicle interior to the combiner side is suppressed by the cover member.

[0007]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a schematic configuration of the present embodiment. In FIG. 1, reference numeral 1 is a front glass of a vehicle 2 and a combiner made of a light-transmissive metal thin film provided on its inner surface by means such as vapor deposition. 3 is attached. Reference numeral 4 denotes an instrument panel (instrument panel) made of a non-translucent material, and an opening window 5 communicating with a projector described later is provided on the upper surface of the instrument panel. Reference numeral 6 denotes a projector provided in the instrument panel 4, and this projector 6 has a built-in display 7 for emitting a display light beam L so as to display driving information by numbers, pictures, etc. It has an optical path 8 through which the display light ray L passes.

On the surface of the display 7, for example, a first polarizing plate 9 whose polarization axis is parallel to the plane of the paper, and a first quarter-wave plate 10 which twists the axial direction of light rays by 45 degrees are provided on the first polarizing plate 9. Are attached in a laminated state.

In addition, in the optical path 8, between the display 7 and the combiner 3, the polarization axis is different from the polarization axis of the first polarizing plate 9 by 90 degrees, that is, the polarization axis is perpendicular to the paper surface. A cover member 13 composed of a second polarizing plate 11 and a second quarter-wave plate 12 which are arranged in parallel with each other is provided at a predetermined angle so that both quarter-wave plates 10 and 12 face each other. .

Reference numeral 14 is a driver, 15 is a display image formed outside and outside the windshield 1, 16 is a landscape, and S is sunlight.

In such a configuration, the vehicle speed detected by, for example, a vehicle speed sensor (not shown) is radiated from the display 7 as a green light ray L, which is in the form of a number, and the light ray L is the first polarized light. The plate 9 turns the polarized light parallel to the plane of the paper, and the first quarter-wave plate 10 twists the optical axis by 45 degrees. Next, when the display light beam L reaches the cover member 13, the optical axis is twisted by 45 degrees by the second quarter-wave plate 12 to become polarized light which is perpendicular to the paper surface and becomes parallel to the polarizing axis of the second polarizing plate 11. The transparent cover member 13 is transmitted therethrough. After that, it is radiated toward the combiner 3 of the windshield 1 and reflected to the driver 14 side, whereby the driver 14 can see the display image 15 on the outside front side of the front glass 1 and the scenery 16 in a superposed manner.

On the other hand, in the sunlight S transmitted through the windshield 1 toward the optical path 8 of the projector 6, a component parallel to the paper surface is reflected to the windshield 1 side by the second polarizing plate 11 of the cover member 13. The reflected light S1 does not reach the combiner 3 because the cover member 13 is inclined and does not interfere with the display image 15.

Further, the component of the sunlight S perpendicular to the paper surface passes through the second polarizing plate 11, and then the optical axis is twisted by 45 degrees by the second ¼ wavelength plate 12 so that the first ¼ wavelength is obtained. The light is reflected on the surface of the wave plate 10, and the optical axis is twisted again by 45 degrees by the second quarter-wave plate 12 so that it is directly crossed with the polarization axis of the second polarizing plate 11. The transmitted light S2 of S does not pass through the cover member 13. Note that, among the transmitted light S2 of the sunlight S, there is one that is transmitted through the first quarter-wave plate 10 and reflected on the surface of the first polarizing plate 9 or the surface of the display 7, but these are slightly Is.

As described above, in the present embodiment, the sunlight S traveling toward the light path 8 of the display light L is reflected by the cover member 13 toward the combiner 3 side to mislead the display image 15 or to the display 7. It is possible to prevent problems such as reaching the display 7 and heating and degrading it, and the display light L is attenuated by the polarizing plates 9 and 11 and the quarter wavelength plates 10 and 12, but is of a high brightness type. By selecting the display device 7, the display image 15 can be reflected by the combiner 3 and guided to the driver 14 side as in the conventional case, and the display image 15 can be seen overlapping the landscape 16.

By the way, when a commercially available product (manufactured by Nitto Denko: product name NPF-QE-10-39) is used as the polarizing plates 9 and 11, the parallel transmittance is 30.5% and the orthogonal transmittance is 0.05%. The commercially available wave plates 11 and 13 (Lukeo: product name RETAX-1 / 4λ) have a transmittance of 95% or more and a surface reflectance of 4% in the visual wavelength range. When an STN active matrix type liquid crystal display element having a high brightness halogen lamp of cd / m ² as a backlight is selected, the brightness of the display light L from the first polarizing plate 9 is about 36000 cd / m ² . Since it is possible, the brightness of the display light beam L in the combiner 3 is 36000 × 0.95 × 0.95 × 0.305 ≈10,000 cd / m ² . On the other hand, the brightness of the transmitted light S2 traveling toward the combiner 3 side in the sunlight S is 10 ⁶ × 0.305 × 0.95 × 0.04 × 0.95 × 0.0005 ≈5.5 cd / m ² , and L >> S2 .

The present invention is not limited to the above-mentioned embodiment, and various modifications can be made within the scope of the present invention. For example, the display 7 may be a fluorescent display device.

Further, the combiner 3 may be provided near the lower end of the windshield 1 so that the display image 16 can be displayed without overlapping the landscape 17.

[0019]

[Effect of device]

 The present invention forms a display image corresponding to the display light beam in front of the driver as a virtual image by reflecting the display light beam from the display device toward the driver side by a combiner arranged in front of the driver. In the display device for a vehicle, a first polarizing plate and a first quarter-wave plate are provided on the surface of the display, and the polarizing axis of the polarizing plate is different from the polarizing axis of the polarizing plate by 90 degrees. A cover member consisting of the polarizing plate and the second quarter-wave plate is provided at a predetermined angle between the display and the combiner so that the both quarter-wave plates face each other. A display device for a vehicle can be provided which can prevent the sunlight entering the vehicle interior from being reflected to the combiner side by the cover member and can prevent the visibility from being deteriorated and the display from being deteriorated by the sunlight.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

[Explanation of symbols]

 3 Combiner 7 Display 9 First polarizing plate 10 First quarter-wave plate 11 Second polarizing plate 12 Second quarter-wave plate 13 Cover member 14 Driver 15 Display image 16 Landscape L Display light beam S Sun light

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadahiro Uchiyama 1-1190, Fujihashi, Nagaoka City, Niigata Prefecture 1 R & D Center, Nippon Seiki Co., Ltd. (72) Inventor Katsumi Nakashizuka Fujihashi, Nagaoka City, Niigata Prefecture 1-chome 190 1 Nippon Seiki Co., Ltd. R & D Center

Claims (1)

[Scope of utility model registration request] 1. A display image corresponding to the display light beam is formed as a virtual image in front of the driver by reflecting a display light beam from a display device toward the driver side by a combiner arranged in front of the driver. In a vehicular display device for displaying an image, a first polarizing plate and a first quarter-wave plate are provided on the surface of the display, and the polarizing axis is different from the polarizing axis of the polarizing plate by 90 degrees. A cover member composed of a second polarizing plate and a second quarter-wave plate is provided at a predetermined angle between the display and the combiner so that the both quarter-wave plates face each other. Characteristic vehicle display device.